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SingaporeBiotechnology

Laboratory Techniques

4 dot points across 4 inquiry questions. Click any dot point for a focused answer with worked past exam questions where available.

How do you grow bacteria on a plate so that each cell forms a separate, countable colony?

Describe how to culture bacteria on agar and use streaking and spreading to obtain colonies
A focused answer to the O-Level outcome on culturing bacteria. Agar plates and broth, streaking for single colonies, spread plates for counting, and incubation conditions.
8 min answer →

How do factories grow microorganisms in huge tanks and keep the conditions perfect for making a product?

Describe the use of a bioreactor (fermenter) for large-scale culture and the conditions it controls
A focused answer to the O-Level outcome on bioreactors. The parts of a fermenter, the conditions it controls, batch versus continuous culture, and calculating product yield.
9 min answer →

How do you measure out a few millionths of a litre accurately, and make up a solution to the concentration you need?

Describe how to use a micropipette accurately and how to prepare a solution of a required concentration
A focused answer to the O-Level outcome on micropipetting and solutions. Using a micropipette correctly, avoiding errors, and calculating how to make a solution of a required concentration.
9 min answer →

How do you dilute a sample millions of times in steps, and use the dilution to count the cells in the original?

Describe serial dilution and use the dilution factor to calculate concentrations and cell numbers
A focused answer to the O-Level outcome on serial dilution. How a step-by-step dilution series works, dilution factors, and how to calculate the cell number in the original sample.
9 min answer →